Thioethers, methods for their preparation, and compositions including such thioethers

ABSTRACT

Disclosed are thioethers, methods for preparing such thioethers, and curable compositions, such as coating and sealant compositions, that include such thioethers. The thioethers can be the reaction product of (a) an alpha, omega dihalo organic compound, (b) a metal hydrosulfide and (c) a metal hydroxide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/108,782, filed Apr. 24, 2008.

FIELD OF THE INVENTION

The present invention is directed to thioethers, methods for preparingsuch thioethers, and curable compositions, such as coating and sealantcompositions, that include such thioethers.

BACKGROUND OF THE INVENTION

Thiol-terminated sulfur-containing compounds are known to be well-suitedfor use in various applications, such as aerospace sealant compositions,due, in large part, to their fuel-resistant nature upon cross-linking.Other desirable properties for aerospace sealant compositions includelow temperature flexibility, short curing time (the time required toreach a predetermined strength) and elevated-temperature resistance,among others. Sealant compositions exhibiting at least some of thesecharacteristics and containing thiol-terminated sulfur-containingcompounds are described in, for example, U.S. Pat. Nos. 2,466,963,4,366,307, 4,609,762, 5,225,472, 5,912,319, 5,959,071, 6,172,179,6,232,401, 6,372,849 and 6,509,418.

Polythioethers that are liquid at room temperature and pressure and thathave excellent low temperature flexibility and fuel resistance, such asare disclosed in U.S. Pat. No. 6,172,179, are often desired in aerospacesealant applications, for example. Unfortunately, such polythioetherscan be relatively expensive to manufacture due to raw material costs,particularly certain polythiols from which such polythioethers arederived. As a result, it would be desirable to provide novel thioethersthat exhibit acceptable, sometimes surprisingly excellent, properties,such as fuel-resistance and elevated-temperature resistance, as comparedto those described in the prior art but that are capable of beingproduced without the use of a polythiol and, therefore, are capable ofbeing produced at reduced cost as compared to polythioethers derivedfrom certain polythiols.

The present invention has been developed in view of the foregoing.

SUMMARY OF THE INVENTION

In certain respects, the present invention is directed to thioethers.The thioethers of the present invention comprise the structure (I):

in which:

(a) each R, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; a C₃₋₁₀ branchedalkylene group, such as a C₃₋₆ branched or a C₃₋₆ branched alkylenegroup having one or more pendant groups which can be, for example, alkylgroups, such as methyl or ethyl groups; a C₆₋₈ cycloalkylene group; aC₆₋₁₄ alkylcycloalkylene, such as a C₆₋₁₀ alkylcycloalkylene group; or aC₈₋₁₀ alkylarylene group;

(b) each R₁, which may be the same or different, denotes a hydrogen, aC₁₋₁₀ n-alkylene group, such as a C₁₋₆ n-alkylene group; a C₃₋₁₀branched alkylene group, such as a C₃₋₆ branched alkylene group havingone or more pendant groups which can be, for example, alkyl groups, suchas methyl or ethyl groups; a C₆₋₈ cycloalkylene group; a C₆₋₁₄alkylcycloalkylene, such as a C₆₋₁₀ alkylcycloalkylene group; or a C₈₋₁₀alkylarylene group;

(c) each X, which may be the same or different, denotes O or S;

(d) p has a value of 1 to 5;

(e) q has a value of 1 to 5; and

(f) n has a value of at least 1, such as at least 2, and in some cases 2to 60, 3 to 60, or 25 to 35.

In other respects, the present invention is directed to thioethers thatcomprise the structure (I), wherein:

(a) each R denotes a C₂ n-alkylene group;

(b) each R₁ denotes hydrogen;

(c) each X denotes O;

(d) p has a value of 1;

(e) q has a value of 1; and

(f) n has a value of at least 1, such as at least 2, and in some cases 2to 60, 3 to 60, or 25 to 35.

In yet other respects, the present invention is directed to thioethersthat are the reaction product of reactants comprising: (a) an alpha,omega dihalo organic compound, (b) a metal hydrosulfide, and (c) a metalhydroxide.

In still other respects, the present invention is directed tocompositions, such as coating and sealant compositions, that comprisesuch thioethers, including compositions that comprise two or moresulfur-containing polymers, at least one of which comprising suchthioethers.

The present invention is also directed to, inter alia, methods formaking such thioethers.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

For purposes of the following detailed description, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary.Moreover, other than in any operating examples, or where otherwiseindicated, all numbers expressing, for example, quantities ofingredients used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

As indicated, certain embodiments of the present invention are directedto thioethers. As used herein, the term “thioether” refers to compoundscomprising at least one, often at least two thioether linkages, that is“—C—S—C—” linkages. In certain embodiments, such compounds are apolymer. As used herein, “polymer” refers to oligomers and bothhomopolymers and copolymers. Unless stated otherwise, if used herein,molecular weights are number average molecular weights for polymericmaterials indicated as “Mn” and obtained by gel permeationchromatography using a polystyrene standard in an art-recognized manner.

Certain embodiments of the present invention are directed to thioethersthat comprise a structure having the formula (I), described earlier.More particularly, with respect to formula (I), in certain embodiments:(a) each R, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; (b) each R₁, whichmay be the same or different, denotes a hydrogen or a C₁₋₁₀ n-alkylenegroup, such as a C₁₋₆ n-alkylene group; (c) each X denotes O; (d) p hasa value of from 1 to 5; (e) q has a value of 1 to 5; and (f) n has avalue of at least 1, often at least two, such as 2 to 60, 3 to 60, or,in some cases 25 to 35. Furthermore, in certain embodiments, withrespect to formula (I): (a) R denotes a C₂ n-alkylene group; (b) R₁denotes a hydrogen; (c) X denotes O; (d) p has a value of 1; (e) q has avalue of 1; and (f) n has a value of at least 1, often at least two,such as 2 to 60, 3 to 60, or, in some cases 25 to 35.

Thioethers of the present invention that include terminal —SH groups are“uncapped.” In certain embodiments of the present invention, suchuncapped thioethers comprise the structure (II):

wherein: (a) each R, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; (b) each R₁, whichmay be the same or different, denotes a hydrogen or a C₁₋₁₀ n-alkylenegroup, such as a C₁₋₆ n-alkylene group; (c) each X denotes O or S; (d) phas a value of 1 to 5; (e) q has a value of 1 to 5; and (f) n has avalue of at least 1, in some cases at least 2, such as 2 to 60, 3 to 60,or 25 to 35. Furthermore, in certain embodiments, with respect toformula (II): (a) each R denotes a C₂ n-alkylene group; (b) each R₁denotes a hydrogen; (c) each X denotes O; (d) p has a value of 1; (e) qhas a value of 1; and (f) n has a value of at least 1, in some cases atleast 2, such as 2 to 60, 3 to 60, or 25 to 35.

In certain embodiments, the thioethers of the present invention areformed from reactants comprising, or, in some cases, consistingessentially of, or, in yet other cases, consisting of, (i) an alpha,omega dihalo organic compound, such as “x” moles thereof, (ii) a metalhydrosulfide, such as ≧2x moles thereof, (iii) a metal hydroxide, suchas ≧2x moles thereof and optionally, (iv) a capping agent and/or (v) apolyfunctionalizing agent (as described below). In certain embodiments,the thioethers of the present invention are formed from reactants thatare substantially free, or, in some cases, completely free, of anypolythiol. As used herein, the term “substantially free” means that thematerial being discussed is present, if at all, as an incidentalimpurity. In other words, the material does not affect the properties ofthe thioether or the composition in which the thioether is used. As usedherein, the term “completely free” means that the material beingdiscussed is not present at all. In certain embodiments, the thioetherof the present invention is produced by reacting the reactants (i),(ii), and (iii) in the presence of a phase transfer catalyst.

Suitable alpha, omega dihalo organic compounds have the chemicalformula: X—R—Y, where X and Y are halogens and R is an organic group. Xand Y may be different halogen atoms or the same halogen atoms. By“alpha, omega” is meant that the halogen atoms are believed to beattached to opposite ends of the organic group. Suitable halogensinclude, for example, chlorine, bromine, and iodine. Suitable organicgroups include, for example, alkyl groups with 3 or more carbon atoms,aryl groups, alkylaryl groups, alkoxy groups, and arylalkoxy groups. Incertain embodiments, the organic group comprises an alkoxy group,specific examples of which can be illustrated by the chemical formulas(III) and (IV):

—CH₂—CH₂—O—CH₂—O—CH₂—CH₂—  (III)

—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—  (IV).

In some embodiments, the organic group may comprise a sulfur atom,specific examples of which can be illustrated by the chemical formulas(V) and (VI):

—CH₂—CH₂—S—CH₂—CH₂—  (V)

—CH₂—CH₂—S—CH₂—CH(CH₃)—  (VI).

One specific example of an alpha, omega dihalo organic compound that issuitable for use in the present invention is bis(2-chloroethyl) formal.

Suitable metal hydrosulfides have the formula M—SH, where M is a metal.Specific examples of suitable metal hydrosulfides include, for example,sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide,rubidium hydrosulfide, cesium hydrosulfide, as well as mixtures of twoor more of the foregoing. These metal hydrosulfides can be used, forexample, as hydrates, aqueous mixtures or anhydrous.

Suitable metal hydroxides have the formula M—(OH)_(x), where M is ametal and x is 1, 2, or 3. Specific examples of suitable metalhydroxides include, for example, lithium hydroxide, sodium hydroxide,potassium hydroxide, calcium hydroxide, barium hydroxide, as well asmixtures of two or more of the foregoing. These metal hydroxides can beused, for example, as hydrates, aqueous mixtures or anhydrous.

Suitable phase transfer catalysts (PTCs) include, for example,quaternary ammonium salts, phosphonium salts, and crown ethers. A moredetailed description of phase transfer catalysis and descriptions ofcompounds suitable as PTCs can be found in E. V. Dehmlow, “Catalysis,Phase Transfer,” in Volume 5 of the Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th edition, Wiley (1996). Further examples of PTC's can befound in JP04046931, to T. Tozawa et. al. In certain embodiments of thepresent invention, the phase transfer catalyst comprisestetrabutylammonium bromide, 18-crown-6, tetraphenylphosphonium halide,and/or methyltributylammonium chloride. In certain embodiments, asuitable amount of PTC is 0.01 to 10 mole % based on the moles of thealpha, omega dihalo organic compound or compounds, such as 0.05 to 2.0mole %.

In certain embodiments, the uncapped thioether described above is aliquid at room temperature. Moreover, in certain embodiments, thepreviously described thioether has a viscosity, at 100% solids, of nomore than 1500 poise, such as 2-500 or, in some cases, 40-500 poise, ata temperature of about 25° C. and a pressure of about 760 mm Hgdetermined according to ASTM D-2849 §79-90 using a Brookfield CAP 2000viscometer, as described in the Examples. Any endpoint within theforegoing ranges can also be used.

In certain embodiments, the uncapped thioether described above has anumber average molecular weight of 300 to 10,000 grams per mole, such as1,000 to 8,000 grams per mole, the molecular weight being determined bygel permeation chromatography using a polystyrene standard. Anyendpoints within the foregoing ranges can also be used.

In certain embodiments, the T_(g) of the thioether of the presentinvention is not higher than −55° C., such as not higher than −60° C.

In certain embodiments, the thioethers of the present invention are“capped”, i.e., they have terminal groups other than unreacted —SHgroups, such as those having a structure according to formula (VII):

A-(—R³)₂  (VII)

wherein: (a) A denotes a structure having the formula (I); and (b) eachR³, which may be the same or different, comprises a terminal groupsother than a thiol, such as —OH, alkyl, such as a C₁₋₁₀ n-alkyl group,alkylene, such as a C₁₋₁₀ n-alkylene group, —NCO,

an amine group, or a hydrolyzable functional group, such as a silanegroup, e.g.,

wherein R and R₁ each independently represent an organic group and x is1, 2, or 3. It should be understood that R³ may include any of a varietyof groups linking A to a terminal group. As indicated, suitable terminalgroups include, for example: (i) —OH, such as could be obtained by, forexample, (a) reacting an uncapped thioether of the present inventionwith a monoxide, such as ethylene oxide, propylene oxide, and the like,in the presence of a base, or (b) reacting an uncapped thioether of thepresent invention with an olefinic alcohol, such as, for example, allylalcohol, or a monovinylether of a diol, such as, for example, ethyleneglycol monovinyl ether, propylene glycol monovinyl ether, and the like,in the presence of a free radical initiator; (ii) alkyl, such as couldbe obtained by reacting an uncapped thioether of the present inventionwith an alkylene; (iii) alkylene, such as could be obtained by reactingan uncapped thioether of the present invention with an diolefin; (iv)—NCO, such as could be obtained by reacting an uncapped thioether of thepresent invention with a polyisocyanate;

such as could be obtained by reacting an uncapped thioether of thepresent invention with a glycidylolefin, wherein the olefinic group may,for example, be an alkylene group or an oxyalkylene group having from 3to 20, such as 3 to 5, carbon atoms, specific examples of which includeallyl glycidyl ether, 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene,1,2-epoxy-9-decene, 4-vinyl-1-cyclohexene 1,2-epoxide, butadienemonoepoxide, isoprene monoepoxide, and limonene monoepoxide; or (vi) ahydrolyzable functional group, such as could be obtained by reacting anuncapped thioether of the present invention with an olefinicalkoxysilane, such as vinyltrimethoxysilane, vinyltriethoxysilane, andvinylmethyldimethoxysilane, among others.

In certain embodiments, the present invention comprises a cappedthioether comprising an —NCO terminal group. As mentioned, such athioether can be obtained by reacting an uncapped thioether of thepresent invention with a polyisocyanate, though other routes forobtaining such a capped thioether can be envisioned.

Any polyisocyanate can be used, including, for example, aliphatic and/oraromatic polyisocyanates. In some embodiments, however, it is desirableto utilize a polyisocyanate, such as a diisocyanate, that has differingreactivity caused, for example, by steric hindrance. Examples of suchpolyisocyanates include isophorone diisocyanate, 2,4-toluenediisocyanate, and mixtures of toluene diisocyanates having a majority ofthe species of differing reactivity, such as 80 percent 2,4-toluenediisocyanate and 20 percent 2,6-toluene diisocyanate, by weight.Moreover, in certain embodiments, it is desirable to employ asulfur-containing diisocyanate, such as, for example, the reactionproduct of a diisocyanate, such as any of those described above, with asulfur diol, such as those having the formula: S_(f)(ROH)₂ wherein f is1 or 2, and R is an alkyl of 1 to 10 carbons atoms, such as 2 to 4carbon atoms, or an oxyalkyl wherein the alkyl is 1 to 10 carbon atoms,such as 2 to 4 carbon atoms. Non-limiting examples of such sulfur diolsare 2,2′-thiodiethanol and 2,2′-thiodipropanol.

In certain embodiments, the —NCO capped thioether described above is aliquid at room temperature. Moreover, in certain embodiments, such athioether has a viscosity, at 100% solids, of 10 to 1000 poise, such as500 to 1000 poise, as measured at a temperature of about 25° C. and apressure of 760 mm Hg determined according to ASTM D-2849 §79-90 using aBrookfield CAP 2000 viscometer, as described in the Examples. Any endpoint within the foregoing ranges can be used.

The polyisocyanate and uncapped thioether are typically reacted inamounts such that there is a molar excess of —NCO groups to —SH groupspresent. In certain embodiments, >1 to 8, such as >1 to 3 moles of —NCOgroups are present per 1 mole of —SH groups. The Examples herein furtherillustrate suitable methods for making an —NCO capped thioether of thepresent invention.

In certain embodiments, it is desirable to produce a capped thioethercomprising functional groups reactive with —NCO groups, such as anamine/hydroxyl-functional thioether. As used herein,“amine/hydroxy-functional thioether” refers to thioethers containing oneor more amine functional groups and/or one or more hydroxy functionalgroups. In certain embodiments of the present invention, theamine/hydroxy-functional thioether comprises at least one, in some casestwo, primary amine groups, at least one, in some cases two, secondaryamine groups, and/or at least one, in some cases two, hydroxy groups.

In certain embodiments, the foregoing amine/hydroxyl-functionalthioether is derived from an epoxy capped thioether, such as by reactingone or more epoxy capped thioethers of the type previously describedwith an excess of one or more amines, such as monoamine and/orpolyamine, i.e., the amine and epoxy capped thioether are reacted inamounts such that there is a molar excess of amine groups to epoxygroups present. In certain embodiments, >1 to 5, such as >1 to 3 molesof amine groups are present per 1 mole of epoxy groups. As used herein,the term “polyamine” refers to a compound comprising two or more aminegroups per molecule. The monoamine(s) and polyamine(s) can beindependently chosen from primary amines (—NH₂), secondary amines (—NH—)and combinations thereof.

Suitable monoamines include mono and dialkyl amines and mixed alkyl-arylamines and substituted amines in which the substituents do notdetrimentally affect the epoxy-amine reaction. Specific examples ofthese amines are, without limitation, ethylamine, diethylamine,propylamine, dipropylamine, butylamine, dibutylamine, pentylamine,dipentylamine, hexylamine, dihexylamine, methylbutylamine, benzylamine,methyl ethyl amine, among others. Examples of substituted amines arehydroxyl-containing amines such as alkanolamines, dialkanolamines, alkylalkanolamines and aryl alkanolamines containing from 2 to 18 carbonatoms in the alkanol, alkyl and aryl chains. Specific examples includeethanolamine, diethanolamine, N-methylethanolamine, diethanolamine andN-phenylethanol.

In certain embodiments, a polyamine is employed, such as those having atleast two primary amine groups. Polyamines suitable for use in theproduction of the amine/hydroxy functional thioethers of the presentinvention include, for example, aliphatic polyamines, cycloaliphaticpolyamines, aromatic polyamines and mixtures thereof.

In certain embodiments, the polyamine is a sulfur-containing polyamine.Non-limiting examples of suitable sulfur-containing polyamines areisomers of benzenediamine-bis(methylthio)-, such as1,3-benzenediamine-4-methyl-2,6-bis(methylthio)- and1,3-benzenediamine-2-methyl-4,6-bis(methylthio)-, the structures ofwhich are illustrated below:

Such sulfur-containing polyamines are commercially available fromAlbemarle Corporation under the tradename ETHACURE® 300.

Suitable polyamines for use in the present invention also include, forexample, materials having the following chemical structure:

wherein R₁ and R₂ can each be independently chosen from methyl, ethyl,propyl, and isopropyl groups, and R₃ can be chosen from hydrogen andchlorine. Non-limiting specific examples of such amines include thosewherein R₁ is C₃H₇, R₂ is C₃H₇, and R₃ is H); those wherein R₁ is CH₃,R₂ is CH₃, and R₃ is H); those wherein R₁ is CH₃, R₂ is C₂H₅, and R₃ isH); those wherein R₁ is C₂H₅, R₂ is C₂H₅, and R₃ is H, those wherein R₁is CH₃, R₂ is C₃H₇, and R₃ is H, and those wherein R₁ is C₂H₅, R₂ isC₂H₅, and R₃ is Cl.

In certain embodiments, the polyamine comprises a diamine, such as4,4′-methylenebis(3-chloro-2,6-diethylaniline),2,4-diamino-3,5-diethyl-toluene, 2,6-diamino-3,5-diethyl-toluene andmixtures thereof (collectively “diethyltoluenediamine” or “DETDA”), asulfur-containing diamine, such as ETHACURE® 300 described above,4,4′-methylene-bis-(2-chloroaniline) and mixtures thereof. Othersuitable diamines include 4,4′-methylene-bis(dialkylaniline),4,4′-methylene-bis(2,6-dimethylaniline),4,4′-methylene-bis(2,6-diethylaniline),4,4′-methylene-bis(2-ethyl-6-methylaniline),4,4′-methylene-bis(2,6-diisopropylaniline),4,4′-methylene-bis(2-isopropyl-6-methylaniline), and/or4,4′-methylene-bis(2,6-diethyl-3-chloroaniline).

Further, non-limiting examples of suitable polyamines can includeethyleneamines, such as, but not limited to, ethylenediamine (EDA),diethylenetriamine (DETA), triethylenetetramine (TETA),tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), piperazine,morpholine, substituted morpholine, piperidine, substituted piperidine,diethylenediamine (DEDA), 2-amino-1-ethylpiperazine and mixturesthereof. In certain embodiments, the polyamine can be chosen from one ormore isomers of C₁-C₃ dialkyl toluenediamine, such as, but not limitedto, 3,5-dimethyl-2,4-toluenediamine, 3,5-dimethyl-2,6-toluenediamine,3,5-diethyl-2,4-toluenediamine, 3,5-diethyl-2,6-toluenediamine,3,5-diisopropyl-2,4-toluenediamine, 3,5-diisopropyl-2,6-toluenediamine,and mixtures thereof. In certain embodiments, the polyamine can bemethylene dianiline or trimethyleneglycol di(para-aminobenzoate) ormixtures thereof.

In certain embodiments, the polyamine can include at least one of thefollowing general structures:

In certain embodiments, the polyamine can include one or more methylenebis anilines, one or more aniline sulfides, and/or one or morebianilines which can be represented by the following general structures:

wherein R₃ and R₄ can each independently represent C₁ to C₃ alkyl, andR₅ can be chosen from hydrogen and halogen, such as but not limited tochlorine and bromine.

In certain embodiments, the polyamine can include materials which can berepresented by the following general structure:

where R₂₀, R₂₁, R₂₂, and R₂₃ can be each independently chosen from H, C₁to C₃ alkyl, CH₃—S— and halogen, such as but not limited to chlorine orbromine. In certain embodiments, the polyamine represented by theimmediately preceding structure can be diethyl toluene diamine (DETDA)wherein R₂₃ is methyl, R₂₀ and R₂₁ are each ethyl and R₂₂ is hydrogen.In certain embodiments, the polyamine can be 4,4′-methylenedianiline.

In certain embodiments, the amine/hydroxy functional thioether describedabove is a liquid at room temperature. Moreover, in certain embodiments,the previously described amine/hydroxy functional thioether has aviscosity, at 100% solids, of 10 to 150 poise, such as 50 to 100 poise,as measured at a temperature of about 25° C. and a pressure of 760 mm Hgdetermined according to ASTM D-2849 §79-90 using a Brookfield CAP 2000viscometer. Any end point within the foregoing ranges can be used.

In certain embodiments, the amine/hydroxy functional thioether describedabove has a number average molecular weight of 500 to 10,000 grams permole, such as 1,000 to 5,000 grams per mole, the molecular weight beingdetermined by gel permeation chromatography using a polystyrenestandard. Any endpoints within the foregoing ranges can be used.

The Examples herein further illustrate suitable methods for making anamine/hydroxy functional thioether suitable for use in the presentinvention.

In certain embodiments, the thioether of the present invention has theformula (VIII):

B-(A-R₃)_(z)  (VIII)

in which: (a) B denotes a z-valent residue of a polyfunctionalizingagent; (b) A denotes a structure having the formula (I); (c) each R₃,which may be the same or different, comprises —SH; —H, —OH, alkyl, suchas a C₁₋₁₀ n-alkyl group, alkylene, such as a C₁₋₁₀ n-alkylene group,—NCO,

an amine group, or a hydrolyzable functional group, such as a silanegroup, e.g.,

wherein R and R₁ each independently represent an organic group and x is1, 2, or 3; and (d) z is an integer from 3 to 6.

Suitable polyfunctionalizing agents include, for example, trihaloorganic compounds, such as trihalo alkyl compounds, for example, trihalopropane. Suitable halogens again include, for example, chlorine,bromine, and iodine. In certain embodiments, the polyfunctionalizingagent comprises 1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,1,1,1-tris(chloromethyl)ethane, and/or 1,3,5-tris(chloromethyl)benzene.In certain embodiments, a suitable amount of trihalo organic compound(s)is greater than 0 to 10 moles of trihalo organic compound per 100 molesof alpha, omega dihalo organic compound(s), such as 0.5 to 5 moles oftrihalo organic compound(s) per 100 moles of alpha, omega dihalo organiccompound(s), or, in some cases 3 moles of trihalo organic compound(s)per 100 moles of alpha, omega dihalo organic compounds. The trihaloorganic compound(s), if used, is often mixed with the alpha, omegadihalo organic compound(s) so that the mixed halo compounds are addedtogether to the reaction mixture.

As indicated, certain embodiments of the present invention are directedto compositions, such as sealant, coating, and/or electrical pottingcompositions that include one or more of the previously describedthioethers. As used herein, the term “sealant composition” refers to acomposition that is capable of producing a film that has the ability toresist atmospheric conditions, such as moisture and temperature and atleast partially block the transmission of materials, such as water,fuel, and other liquid and gasses. In certain embodiments, the sealantcompositions of the present invention are useful, e.g., as aerospacesealants and linings for fuel tanks. In certain embodiments, thecomposition comprises a thioether as described above, a curing agent anda filler.

In certain embodiments, the compositions of the present inventioncomprise, in addition to a thioether as described earlier, one or moreadditional sulfur-containing polymers. As used herein, the term“sulfur-containing polymer” refers to any polymer having at least onesulfur atom, including, but not limited to, polymeric thiols,polythiols, thioethers, polythioethers and polysulfides. A “thiol”, asused herein, refers to a compound comprising a thiol or mercaptan group,that is, an “SH” group, either as the sole functional group or incombination with other functional groups, such as hydroxyl groups, as isthe case with, for example, thioglycerols. A “polythiol” refers to sucha compound having more than one SH group, such as a dithiol or higherfunctionality thiol. Such groups are typically terminal and/or pendentsuch that they have an active hydrogen that is reactive with otherfunctional groups. As used herein, the term “polysulfide” refers to anycompound that comprises a sulfur-sulfur linkage (—S—S—). A “polythiol”can comprise both a terminal and/or pendant sulfur (—SH) and anon-reactive sulfur atom (—S— or (—S—S—)). Thus, the term “polythiol”generally encompasses “polythioether” and “polysulfide” as well.Suitable sulfur-containing polymers include, for example, thosedisclosed in U.S. Pat. Nos. 6,172,179, 6,509,418 and 7,009,032,incorporated by reference herein. In certain embodiments, therefore, thecompositions of the present invention comprise a polythioether thatincludes a structure having the formula (IX):

—R¹—[—S—(CH₂)₂—O—[—R²—O—]_(m)—(CH₂)₂—S—R¹]_(n)—  (IX)

wherein: (1) R¹ denotes a C₂₋₆ n-alkylene, C₃₋₆ branched alkylene, C₆₋₈cycloalkylene or C₆₋₁₀ alkylcycloalkylene group,—[(—CH₂—)_(p)—X—]_(q)—(—CH₂—)_(r)—, or —[(CH₂—)_(p)—X—]_(q)—(CH₂—)_(r)—in which at least one —CH₂— unit is substituted with a methyl group; (2)R² denotes a C₂₋₆ n-alkylene, C₂₋₆ branched alkylene, C₆₋₈ cycloalkyleneor C₆₋₄₀ alkylcycloalkylene group, or —[(CH₂—)_(p)—X-]_(q)—(—CH₂—)_(r)—,X denotes one selected from the group consisting of O, S and —NR⁶—, R⁶denotes H or methyl; (3) m is a rational number from 0 to 10; (4) n isan integer from 1 to 60; (5) p is an integer from 2 to 6; (6) q is aninteger from 1 to 5, and (7) r is an integer from 2 to 10. Suchpolythioethers are described in U.S. Pat. No. 6,172,179 at col. 2, line29 to col. 4, line 34, the cited portion of which being incorporatedherein by reference.

Any sulfur-containing polymer used according to the present inventioncan further comprise additional functionality, including but not limitedto hydroxyl functionality and epoxy functionality.

In certain embodiments, the thioether of the present invention ispresent in the composition of the present invention in an amount of atleast 30 weight percent, such as least 40 weight percent, or, in somecases, at least 45 weight percent, based on the total weight ofnon-volatile components in the composition. In certain embodiments, thethioether of the present invention is present in the composition of thepresent invention in an amount of no more than 90 weight percent, suchas no more than 80 weight percent, or, in some cases, no more than 75weight percent, based on the weight of all non-volatile components ofthe composition.

As indicated, certain embodiments of the curable compositions of thepresent invention also comprise a curing agent. Curing agents useful incertain compositions of the invention (particularly in the case in whichan uncapped thioether of the present invention is used) include epoxyresins, for example, hydantoin diepoxide, diglycidyl ether ofbisphenol-A, diglycidyl ether of bisphenol-F, Novolactype epoxides, andany of the epoxidized unsaturated and phenolic resins, as well asunsaturated compounds, such as acrylic and methacrylic esters ofcommercially available polyols, unsaturated synthetic or naturallyoccurring resin compounds, triallylcyanurate, and olefinic terminatedderivatives of the thioethers of the present invention.

Isocyanate functional compounds can also be useful curing agents in thecompositions of the present invention (particularly in the case in whicha capped thioether of the present invention comprising an amine and/orhydroxyl terminal group is used). Suitable isocyanate functionalcompounds include, but are not limited to, polymeric polyisocyanates,non-limiting examples of which include polyisocyanates having backbonelinkages chosen from urethane linkages (—NH—C(O)—O—), thiourethanelinkages (—NH—C(O)—S—), thiocarbamate linkages (—NH—C(S)—O—),dithiourethane linkages (—NH—C(S)—S—) and combinations thereof.

The molecular weight of such a polymeric polyisocyanate can vary. Incertain embodiments, the number average molecular weight (Mn) of eachcan be at least 100 grams/mole, or at least 150 grams/mole, or less than15,000 grams/mole, or less than 5000 grams/mole. The number averagemolecular weight values recited herein can be determined by gelpermeation chromatography (GPC) using polystyrene standards.

Non-limiting examples of suitable polyisocyanates, also includenon-polymeric aliphatic polyisocyanates, cycloaliphatic polyisocyanateswherein one or more of the isocyanato groups are attached directly tothe cycloaliphatic ring, cycloaliphatic polyisocyanates wherein one ormore of the isocyanato groups are not attached directly to thecycloaliphatic ring, aromatic polyisocyanates wherein one or more of theisocyanato groups are attached directly to the aromatic ring, andaromatic polyisocyanates wherein one or more of the isocyanato groupsare not attached directly to the aromatic ring.

In certain embodiments, the polyisocyanate includes, but is not limitedto, aliphatic or cycloaliphatic diisocyanates, aromatic diisocyanates,cyclic dimers and cyclic trimers thereof, and mixtures thereof.Non-limiting examples of suitable polyisocyanates include, but are notlimited to, Desmodur N 3300 (hexamethylene diisocyanate trimer) andDesmodur N 3400 (60% hexamethylene diisocyanate dimer and 40%hexamethylene diisocyanate trimer), which are commercially availablefrom Bayer.

In certain embodiments, the polyisocyanate includes dicyclohexylmethanediisocyanate and/or isomeric mixtures thereof. As used herein, the term“isomeric mixtures” refers to a mixture of the cis-cis, trans-trans, andcis-trans isomers of the polyisocyanate. Non-limiting examples ofisomeric mixtures for use in the present invention include thetrans-trans isomer of 4,4′-methylenebis(cyclohexyl isocyanate),hereinafter referred to as “PICM” (para-isocyanato cyclohexylmethane),the cis-trans isomer of PICM, the cis-cis isomer of PICM, and mixturesthereof. In certain embodiments, the isomeric mixture can contain from10-100 percent of the trans,trans isomer of 4,4′-methylenebis(cyclohexylisocyanate) (PICM).

Additional diisocyanates that can be used include3-isocyanato-methyl-3,5,5-trimethyl cyclohexyl-isocyanate (“IPDI”) andmeta-tetramethylxylylene diisocyanate(1,3-bis(1-isocyanato-1-methylethyl)-benzene) which is commerciallyavailable from Cytec Industries Inc. under the tradename TMXDI® (Meta)Aliphatic Isocyanate.

As used herein, the terms aliphatic and cycloaliphatic diisocyanatesrefer to 6 to 100 carbon atoms linked in a straight chain or cyclizedhaving two diisocyanate reactive end groups. In certain embodiments, thealiphatic and cycloaliphatic diisocyanates used in the present inventioncan include TMXDI and compounds of the formula R—(NCO)₂ wherein Rrepresents an aliphatic group or a cycloaliphatic group.

Additional non-limiting examples of suitable polyisocyanates include,but are not limited to, ethylenically unsaturated polyisocyanates;alicyclic polyisocyanates; aromatic polyisocyanates wherein theisocyanate groups are not bonded directly to the aromatic ring, e.g.,α,α′-xylylene diisocyanate; aromatic polyisocyanates wherein theisocyanate groups are bonded directly to the aromatic ring, e.g.,benzene diisocyanate or methylene dibenzene diisocyanate, which has thestructure

polyisocyanates containing sulfide and/or disulfide linkages; aromaticpolyisocyanates containing sulfone linkages; sulfonic ester-typepolyisocyanates, e.g.,4-methyl-3-isocyanatobenzenesulfonyl-4′-isocyanato-phenol ester;aromatic sulfonic amide-type polyisocyanates; sulfur-containingheterocyclic polyisocyanates, e.g., thiophene-2,5-diisocyanate;halogenated, alkylated, alkoxylated, nitrated, carbodiimide modified,urea modified and biuret modified derivatives of polyisocyanatesthereof; and dimerized and trimerized products of polyisocyanatesthereof.

In certain embodiments, a diisocyanate of the following structure can beused:

wherein R₁₀ and R₁₁ are each independently C₁ to C₃ alkyl.

Examples of ethylenically unsaturated polyisocyanates include, but arenot limited to, butene diisocyanate and 1,3-butadiene-1,4-diisocyanate.

Examples of alicyclic polyisocyanates include, but are not limited to,isophorone diisocyanate, cyclohexane diisocyanate, methylcyclohexanediisocyanate, bis(isocyanatomethyl)cyclohexane,bis(isocyanatocyclohexyl)methane, bis(isocyanatocyclohexyl)-2,2-propane,bis(isocyanatocyclohexyl)-1,2-ethane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptaneand2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane.

Examples of aromatic polyisocyanates wherein the isocyanate groups arenot bonded directly to the aromatic ring also include, but are notlimited to, bis(isocyanatoethyl)benzene, α,α,α′,α′-tetramethylxylylenediisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene,bis(isocyanatobutyl)benzene, bis(isocyanatomethyl)naphthalene,bis(isocyanatomethyl)diphenyl ether, bis(isocyanatoethyl) phthalate,mesitylene triisocyanate and 2,5-di(isocyanatoethyl)furan, andmeta-xylylene diisocyanate.

Examples of aromatic polyisocyanates having isocyanate groups bondeddirectly to the aromatic ring also include, but are not limited to,phenylene diisocyanate, ethylphenylene diisocyanate, isopropylphenylenediisocyanate, dimethylphenylene diisocyanate, diethylphenylenediisocyanate, diisopropylphenylene diisocyanate, trimethylbenzenetriisocyanate, benzene triisocyanate, naphthalene diisocyanate,methylnaphthalene diisocyanate, biphenyl diisocyanate, ortho-toluidinediisocyanate, ortho-tolylidine diisocyanate, ortho-tolylenediisocyanate, 4,4′-diphenylmethane diisocyanate,bis(3-methyl-4-isocyanatophenyl)methane, bis(isocyanatophenyl)ethylene,3,3′-dimethoxy-biphenyl-4,4′-diisocyanate, triphenylmethanetriisocyanate, polymeric 4,4′-diphenylmethane diisocyanate, naphthalenetriisocyanate, diphenylmethane-2,4,4′-triisocyanate,4-methyldiphenylmethane-3,5,2′,4′,6′-pentaisocyanate, diphenyletherdiisocyanate, bis(isocyanatophenylether)ethyleneglycol,bis(isocyanatophenylether)-1,3-propyleneglycol, benzophenonediisocyanate, carbazole diisocyanate, ethylcarbazole diisocyanate anddichlorocarbazole diisocyanate.

Examples of aromatic polyisocyanates containing sulfide or disulfidelinkages include, but are not limited to,diphenylsulfide-2,4′-diisocyanate, diphenylsulfide-4,4′-diisocyanate,3,3′-dimethoxy-4,4′-diisocyanatodibenzyl thioether,bis(4-isocyanatomethylbenzene)sulfide,diphenyldisulfide-4,4′-diisocyanate,2,2′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethyldiphenyldisulfide-6,6′-diisocyanate,4,4′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethoxydiphenyldisulfide-4,4′-diisocyanate and4,4′-dimethoxydiphenyldisulfide-3,3′-diisocyanate.

Examples of aromatic polyisocyanates containing sulfone linkages alsoinclude, but are not limited to, diphenylsulfone-4,4′-diisocyanate,diphenylsulfone-3,3′-diisocyanate, benzidinesulfone-4,4′-diisocyanate,diphenylmethanesulfone-4,4′-diisocyanate,4-methyldiphenylmethanesulfone-2,4′-diisocyanate,4,4′-dimethoxydiphenylsulfone-3,3′-diisocyanate,3,3′-dimethoxy-4,4′-diisocyanatodibenzylsulfone,4,4′-dimethyldiphenylsulfone-3,3′-diisocyanate,4,4′-di-tert-butyl-diphenylsulfone-3,3′-diisocyanate and4,4′-dichlorodiphenylsulfone-3,3′-diisocyanate.

Examples of suitable polyisocyanates include, but are not limited to,aromatic sulfonic amide-type polyisocyanates, such as4-methyl-3-isocyanato-benzene-sulfonylanilide-3′-methyl-4′-isocyanate,dibenzenesulfonyl-ethylenediamine-4,4′-diisocyanate,4,4′-methoxybenzenesulfonyl-ethylenediamine-3,3′-diisocyanate and4-methyl-3-isocyanato-benzene-sulfonylanilide-4-ethyl-3′-isocyanate.

Amine functional compounds can also be useful curing agents in thecompositions of the present invention (particularly in the case in whicha capped thioether of the present invention comprising an isocyanateterminal group is used). Suitable amines include those described earlierin connection with the preparation of an amine functional thioether ofthe present invention.

In addition, in the case where an uncapped thioether of the presentinvention is used, useful cures can be obtained through oxidativecoupling of the thiol groups using organic and inorganic peroxides(e.g., MnO₂) known to those skilled in the art. Selection of theparticular curing agent may affect the T_(g) of the cured composition.

Depending on the nature of the thioether(s) used in the composition, thecomposition will often contain 90% to 150% of the stoichiometric amount,such as 95 to 125%, of the selected curing agent(s).

In certain embodiments, the compositions of the present inventioncomprise two or more sulfur-containing polymers, such as thioetherscomprising a structure having the formula (I), that have coreactivefunctional groups. For example, and without limitation, in certainembodiments, the compositions of the present invention comprise: (i) an—NCO capped sulfur-containing polymer, such as an —NCO capped thioethercomprising a structure having the formula (I) and/or a polythioethercomprising a structure having the formula (IX); and (ii) anamine/hydroxy capped sulfur-containing polymer, such as an amine/hydroxycapped thioether comprising a structure having the formula (I) and/or apolythioether comprising a structure having the formula (IX).

Fillers useful in the certain embodiments of the compositions of thepresent invention include those commonly used in the art, includingconventional inorganic fillers, such as carbon black and calciumcarbonate (CaCO₃), as well as lightweight fillers. Suitable lightweightfillers include, for example, those described in U.S. Pat. No. 6,525,168at col. 4, lines 23-55, the cited portion of which being incorporatedherein by reference. In certain embodiments, the compositions include 5to 60 weight percent of the filler or combination of fillers, such as 10to 50 weight percent, based on the total weight of the composition.

As will be appreciated, the thioethers, curing agents and fillersemployed in certain compositions of the invention, as well as optionaladditives as described below, should be selected so as to be compatiblewith each other. Selection of compatible ingredients for the inventivecompositions can readily be performed by those skilled in the artwithout recourse to undue experimentation.

In certain embodiments, the compositions of the present invention arecurable at a maximum temperature of 0° C. (i.e., at a temperature of 0°C. or lower), such as −10° C., or, in some cases, −20° C., and have aT_(g) when cured not higher than −55° C., such as not higher than −60°C., or, in some cases, not higher than −65° C.

In addition to the foregoing ingredients, certain compositions of theinvention can optionally include one or more of the following:colorants, thixotropes, accelerators, retardants, adhesion promoters,solvents and masking agents, among other components.

As used herein, the term “colorant” means any substance that impartscolor and/or other opacity and/or other visual effect to thecomposition. The colorant can be added to the coating in any suitableform, such as discrete particles, dispersions, solutions and/or flakes.A single colorant or a mixture of two or more colorants can be used inthe coatings of the present invention.

Example colorants include pigments, dyes and tints, such as those usedin the paint industry and/or listed in the Dry Color ManufacturersAssociation (DCMA), as well as special effect compositions. A colorantmay include, for example, a finely divided solid powder that isinsoluble but wettable under the conditions of use. A colorant can beorganic or inorganic and can be agglomerated or non-agglomerated.Colorants can be incorporated into the coatings by use of a grindvehicle, such as an acrylic grind vehicle, the use of which will befamiliar to one skilled in the art.

Example pigments and/or pigment compositions include, but are notlimited to, carbazole dioxazine crude pigment, azo, monoazo, diazo,naphthol AS, salt type (flakes), benzimidazolone isoindolinone,isoindoline and polycyclic phthalocyanine, quinacridone, perylene,perinone, diketopyrrolo pyrrole, thioindigo, anthraquinone, indanthrone,anthrapyrimidine, flavanthrone, pyranthrone, anthanthrone, dioxazine,triarylcarbonium, quinophthalone pigments, diketo pyrrolo pyrrole red(“DPPBO red”), titanium dioxide, carbon black and mixtures thereof. Theterms “pigment” and “colored filler” can be used interchangeably.

Example dyes include, but are not limited to, those that are solventand/or aqueous based such as phthalo green or blue, iron oxide, bismuthvanadate, anthraquinone, perylene and quinacridone.

Example tints include, but are not limited to, pigments dispersed inwater-based or water miscible carriers such as AQUA-CHEM 896commercially available from Degussa, Inc., CHARISMA COLORANTS andMAXITONER INDUSTRIAL COLORANTS commercially available from AccurateDispersions division of Eastman Chemical, Inc.

As noted above, the colorant can be in the form of a dispersionincluding, but not limited to, a nanoparticle dispersion. Nanoparticledispersions can include one or more highly dispersed nanoparticlecolorants and/or colorant particles that produce a desired visible colorand/or opacity and/or visual effect. Nanoparticle dispersions caninclude colorants such as pigments or dyes having a particle size ofless than 150 nm, such as less than 70 nm, or less than 30 nm.Nanoparticles can be produced by milling stock organic or inorganicpigments with grinding media having a particle size of less than 0.5 mm.Example nanoparticle dispersions and methods for making them areidentified in U.S. Pat. No. 6,875,800 B2, which is incorporated hereinby reference. Nanoparticle dispersions can also be produced bycrystallization, precipitation, gas phase condensation, and chemicalattrition (i.e., partial dissolution). In order to minimizere-agglomeration of nanoparticles within the coating, a dispersion ofresin-coated nanoparticles can be used. As used herein, a “dispersion ofresin-coated nanoparticles” refers to a continuous phase in which isdispersed discreet “composite microparticles” that comprise ananoparticle and a resin coating on the nanoparticle. Exampledispersions of resin-coated nanoparticles and methods for making themare identified in United States Patent Application Publication2005-0287348 A1, filed Jun. 24, 2004, U.S. Provisional Application No.60/482,167 filed Jun. 24, 2003, and U.S. patent application Ser. No.11/337,062, filed Jan. 20, 2006, which is also incorporated herein byreference.

Example special effect compositions that may be used in the compositionsof the present invention include pigments and/or compositions thatproduce one or more appearance effects such as reflectance,pearlescence, metallic sheen, phosphorescence, fluorescence,photochromism, photosensitivity, thermochromism, goniochromism and/orcolor-change. Additional special effect compositions can provide otherperceptible properties, such as opacity or texture. In a non-limitingembodiment, special effect compositions can produce a color shift, suchthat the color of the coating changes when the coating is viewed atdifferent angles. Example color effect compositions are identified inU.S. Pat. No. 6,894,086, incorporated herein by reference. Additionalcolor effect compositions can include transparent coated mica and/orsynthetic mica, coated silica, coated alumina, a transparent liquidcrystal pigment, a liquid crystal coating, and/or any compositionwherein interference results from a refractive index differential withinthe material and not because of the refractive index differentialbetween the surface of the material and the air.

In general, the colorant can be present in any amount sufficient toimpart the desired visual and/or color effect. The colorant may comprisefrom 1 to 65 weight percent of the present compositions, such as from 3to 40 weight percent or 5 to 35 weight percent, with weight percentbased on the total weight of the compositions.

Thixotropes, for example silica, are often used in an amount from 0.1 to5 weight percent, based on the total weight of the composition.

Cure catalysts known to the art, such as amines, often are present in anamount from 0.1 to 5 weight percent, based on the total weight of thecomposition. Specific examples of useful catalysts are, withoutlimitation, 1,4-diaza-bicyclo[2.2.2]octane (DABCO®, commerciallyavailable from Air Products, Chemical Additives Division, Allentown,Pa.) and DMP-30® (an accelerant composition including2,4,6-tris(dimethylaminomethyl)phenol, commercially available from Rohmand Haas. Philadelphia, Pa.). It has been surprisingly discovered,however, that certain embodiments of the present invention will cure atambient conditions even in the absence of any such cure catalyst.

Retardants, such as stearic acid, likewise often are used in an amountfrom 0.1 to 5 weight percent, based on the total weight of thecomposition. Adhesion promoters, if employed, are often present inamount from 0.1 to 15 weight percent, based on the total weight of thecomposition. Suitable adhesion promoters include phenolics, such asMETHYLON phenolic resin available from Occidental Chemicals, andorganosilanes, such as epoxy, mercapto or amino functional silanes, suchas Silquest A-187 and Silquest A-1100 available from MomentivePerformance Materials. Masking agents, such as pine fragrance or otherscents, which are useful in covering any low level odor of thecomposition, are often present in an amount from 0.1 to 1 weightpercent, based on the total weight of the composition.

In certain embodiments, the compositions of the present inventioncomprise a plasticizer which, in at least some cases, may allow thecomposition to include thioether(s) which have a higher T_(g) than wouldordinarily be useful in an aerospace sealant. That is, use of aplasticizer may effectively reduce the T_(g) of the composition, andthus increase the low-temperature flexibility of the cured polymerizablecomposition beyond that which would be expected on the basis of theT_(g) of the thioethers alone. Plasticizers that are useful in certainembodiments of the compositions of the present invention include, forexample, phthalate esters, chlorinated paraffins, and hydrogenatedterphenyls. The plasticizer or combination of plasticizers oftenconstitute 1 to 40 weight percent, such as 1 to 10 weight percent of thecomposition. In certain embodiments, depending on the nature and amountof the plasticizer(s) used in the composition, thioethers of theinvention which have T_(g) values up to −50° C., such as up to −55° C.,can be used.

In certain embodiments, the compositions of the present invention canfurther comprise one or more organic solvents, such as isopropylalcohol, in an amount ranging from, for example, 0 to 15 percent byweight on a basis of total weight of the composition, such as less than15 weight percent and, in some cases, less than 10 weight percent.

In certain embodiments, however, the compositions of the presentinvention are substantially free or, in some cases, completely free, ofany solvent, such as an organic solvent or an aqueous solvent, i.e.,water. Stated differently, in certain embodiments, the compositions ofthe present invention are substantially 100% solids.

In certain embodiments, the compositions, such as the previouslydescribed sealant compositions, are embodied as multi-pack compositions,such as two-pack compositions, wherein one package comprises thepreviously described thioether polymer and the second pack comprises thecuring agent. The previously described additives and other materials canbe added to either package as desired or necessary. The two packages aresimply mixed together at or near the time of use.

The compositions of the present invention can be applied to any of avariety of substrates. Common substrates to which the compositions ofthe present invention are applied can include titanium, stainless steel,aluminum, anodized, primed, organic coated and chromate coated formsthereof, epoxy, urethane, graphite, fiberglass composite, KEVLAR®,acrylics and polycarbonates.

The compositions of the present invention can be applied directly ontothe surface of a substrate or over an underlayer by any suitable coatingprocess known to those of ordinary skill in the art, for example, byextruding, dip coating, direct roll coating, reverse roll coating,curtain coating, spray coating, brush coating, vacuum coating andcombinations thereof. The method and apparatus for applying thecomposition to the substrate may be determined, at least in part, by theconfiguration and type of substrate material.

In certain embodiments, the compositions of the present invention arefuel-resistant. As used herein, the term “fuel resistant” means that thecompositions of the present invention, when applied to a substrate andcured, can provide a cured product, such as a sealant, that has apercent volume swell of not greater than 40%, in some cases not greaterthan 25%, in some cases not greater than 20%, in yet other cases notmore than 10%, after immersion for one week at 140° F. (60° C.) andambient pressure in jet reference fluid (JRF) type 1 according tomethods similar to those described in ASTM D792 or AMS 3269,incorporated herein by reference. Jet reference fluid JRF type 1, asemployed herein for determination of fuel resistance, has the followingcomposition (see AMS 2629, issued Jul. 1, 1989), §3.1.1 et seq.,available from SAE (Society of Automotive Engineers, Warrendale, Pa.)(that is incorporated herein by reference): herein by reference):

Toluene 28 ± 1% by volume Cyclohexane (technical) 34 ± 1% by volumeIsooctane 38 ± 1% by volume Tertiary dibutyl disulfide  1 ± 0.005% byvolume (doctor sweet)

Indeed, it was a surprising discovery that certain embodiments of thepresent invention exhibit excellent fuel-resistance properties (percentvolume swell of not greater than 10% as described above, which is oftenassociated with polysulfides) as well as excellent elevated-temperatureresistance (good tensile strength and elongation properties after 8hours exposure at 360° F., which is often associated withpolythioethers).

In certain embodiments, cured products, such as sealants, of the presentinvention have good low temperature flexibility as determined by knownmethods, for example, by the methods described in AMS (AerospaceMaterial Specification) 3267 §4.5.4.7, AMS-S (MilitarySpecification)-8802B §3.6.16 and MIL-S-29574, and by methods similar tothose described in ASTM (American Society for Testing and Materials)D522-88, which are incorporated herein by reference. Cured formulationshaving good low temperature flexibility are desirable in aerospaceapplications because the formulations are subjected to wide variationsin environmental conditions, such as temperature and pressure, andphysical conditions such as joint contraction and expansion andvibration.

In certain embodiments, compositions of the present invention also curerelatively quickly under ambient conditions. For example, in certainembodiments, the compositions provide a tack free film in no more than 1hour, in some cases no more than ½ hour, after application and cure inambient conditions. For purposes of the present invention tack free timeis measured in accordance with the procedure described in AMS 3265B,§3.6.8, test procedure AS5127/1, §5.8.

In certain embodiments, sealant compositions of the present inventionprovide a cured product, such as a sealant, having an elongation of atleast 100% and a tensile strength of at least 500 psi when measured inaccordance with the procedure described in AMS 3279, §3.3.17.1, testprocedure AS5127/1, §7.7. In fact, it has been discovered that certaincompositions of the present invention that comprise two or morethioethers of the present invention that have coreactive functionalgroups, such as an —NCO capped thioether in combination with anamine/hydroxyl functional thioether, can have exceptional tensilestrength, i.e., at least 700 psi, in some cases at least 800 psi, atleast 900 psi, or even at least 1000 psi, when measured in accordancewith the procedure described in AMS 3279, §3.3.17.1, test procedureAS5127/1, §7.7.

In certain embodiments, sealant compositions of the present inventionprovide a cured product, such as a sealant having a lap shear strengthof greater than 200 psi, in some cases at least 400 psi when measuredaccording to the procedure described in SAE AS5127/1 paragraph 7.8.

As should be apparent from the foregoing description, the presentinvention is also directed to methods for sealing an aperture utilizinga composition of the present invention. These methods comprise (a)applying a composition of the present invention to a surface to seal theaperture; and (b) allowing the composition to cure under, for example,ambient conditions. As will also be appreciated, the present inventionis also directed to aerospace vehicles comprising at least one surfacecoated with a coating composition of the present invention as well asaerospace vehicles comprising at least one aperture that is sealed witha sealant composition of the present invention.

Illustrating the invention are the following examples, which, however,are not to be considered as limiting the invention to their details.Unless otherwise indicated, all parts and percentages in the followingexamples, as well as throughout the specification, are by weight.

EXAMPLES Example 1 Synthesis of Uncapped Thioether

Solid flakes of sodium hydrosulfide hydrate (834.04 g; purity: 70%;10.42 moles) were charged into a 5 liter 4-neck flask followed by water(1.70 Kg). Flask was flushed with nitrogen and stirring was started.Freshly-prepared aqueous sodium hydroxide (306.18 g, concentration: 50%;3.83 moles) was added into the solution of sodium hydrosulfide followedby phase transfer catalyst Aliquat®-175 (available from Cognis) (14.06g, 0.06 mole). Reaction mixture was heated to 160° F. A mixture of2-chloroethylformal (748.89 g, 4.33 moles) and 1,2,3-trichloropropane(19.86 g, 0.13 mole) was added at 160-165° F. over 6.5 hr and stiffingwas continued for another 2 hr. Heating was continued at 175-180° F. for8 hr and at 185-190° F. for 8 hr. Reaction mixture was cooled to ambienttemperature. Partially-emulsified polymeric layer was separated andwashed with five 400 ml portions of water. The last washing was free ofsodium hydrosulfide as indicated by lead acetate paper test. Polymericlayer was then washed with acidified water (400 ml water containing 2 mlof 95% formic acid; pH: 2-3) and dissolved in 1.2 liters of chloroform.Organic portion was separated, filtered through a band of anhydroussodium sulfate and concentrated to give 583 g of a off-white polymer;mercaptan equivalent weight: 1816 (iodine titration method); viscosity:122P (spindle no. 6, @100 RPM; Brookfield Cap 2000 viscometer).

Example 2 Preparation of Sealant Formulation

Part A of the sealant formulation was prepared by mixing 59.90 parts byweight of the polythioether of Example 1, 39.00 parts by weight calciumcarbonate, 0.60 parts by weight of titanium dioxide, and 0.50 parts byweight of 1,4-diaza-bicyclo[2.2.2]octane (DABCO®, commercially availablefrom Air Products, Chemical Additives Division, Allentown, Pa.).

Part B of the sealant formulation was prepared by mixing 0.90 parts byweight of an epoxysilane adhesion promoter, 11.10 parts by weight HB-40modified polyphenyl (commercially available from Solutia, Inc.), 41.60parts by weight calcium carbonate, 46.20 parts by weight Epon 828 epoxyresin, and 0.20 parts by weight carbon black.

The sealant was made for testing by mixing 100 parts of Part A and 14parts of Part B. A sealant prepared from the above composition exhibitedthe properties set forth in Table 1 (tested according to methods in SAEAS5127/1 (except as noted).

TABLE 1 Result Property Application Time 2 Hours Tack Free Time 4 Hours24 Hours Hardness 48 Shore A 14 Days Hardness 52 Shore A Volume Swell -JRF Type I 6% 7 days @ 140° F. Weight Loss - JRF Type I 5% 7 days @140°F. Tensile & Elongation Standard Cure 7 days 300psi/400% 7 Days at 140°F. in JRF 250psi/400% Type I 8 Hours @ 360° F. 180psi/130% AdhesionTested on Mil C-27725 panel Standard Cure 7 days 43 pli, 100% CohesiveFailure 7 Days at 140° F. in JRF 35 pli, 100% Cohesive Failure Type I

Example 3 Synthesis of Uncapped Thioether

Solid flakes of sodium hydrosulfide hydrate (1007.90 g; purity: 72%;12.96 moles) were charged into a 5-liter 4-neck flask followed by water(2.05 Kg). Flask was flushed with nitrogen and stirring was started.Phase transfer catalyst A-175 (17.00 g, 0.07 mole) was added andreaction mixture was heated to 170° F. Addition of a mixture of2-chloroethylformal (919.10 g, 5.31 moles) and 1,2,3-trichloropropane(16.00 g, 0.11 mole) was started at a rate of ˜5.00 g/min. After about10 minutes, addition of a freshly-prepared solution of aqueous sodiumhydroxide (360.00 g, concentration: 50%; 4.50 moles) was started at arate of ˜1.86 g/min. Addition of the chlorides lasted for 3 hr while theaddition period for the solution of sodium hydroxide was 3 hr 5 min.Reaction temperature was raised to 212° F. and heating was continued for3.75 hr. Reaction mixture was cooled to ambient temperature. Aqueouslayer was removed and the polymeric layer was washed with five 500 mlportions of water. The last washing was almost free of sodiumhydrosulfide as indicated by lead acetate paper test. Polymeric layerwas then washed with acidified water (500 ml water containing 10 ml ofglacial acetic acid) followed by three additional 500 ml portions ofwater. Polymer layer was separated and dried at 190-210° F./2-5 mm for1.5 hr; Yield: 631 g; color: light grey; mercaptan equivalent weight:1042 (iodine titration method); viscosity: 42 Poise (spindle no. 6@100RPM, 25° C. Brookfield Cap 2000 Viscometer).

Example 4 Synthesis of Epoxy-Capped Thioether

Polymer of Example 3 (576.91 g; 0.55 equivalents; mercaptan equivalent:1042) was charged into a 1-liter, 4-neck, round-bottom flask. Reactionflask was flushed with nitrogen, stirring was started and the reactionmixture was heated to 70° C. A homogeneous mixture of allyl glycidylether (75.83 g, 0.66 equivalents) and a solution of radical initiator[0.72 g of Vazo®67 {Du Pont's 2,2′-azobis(2-methylbutyronitrile)} in 2ml of toluene] was added into the polymer over 1 hr 42 minutes. Twentytwo additional portions (0.17 g each) of Vazo®67 were added at every˜1.5 hr over a period of 30 hr. The mercaptan equivalent of the reactionmixture was 153,633. Such a high value indicated completion of thereaction. Unconsumed allyl glycidyl ether was removed by evacuating thereaction mixture at 160-170° F./5-10 mmHg for 2.5 hr to provide 640 g ofa liquid epoxy-capped polymer having a faint yellow color, viscosity of80 Poise, and epoxy equivalent value of 1122.

Example 5 Synthesis of Uncapped Thioether

Solid flakes of sodium hydrosulfide hydrate (4434.76 g; purity: 72%;57.02 moles) were charged into a 22-liter 3-neck flask followed by water(9.02 Kg). Flask was flushed with nitrogen and stirring was started.Phase transfer catalyst Aliquat® A-175 (74.80 g, 0.32 mole) was addedand reaction mixture was heated to 170° F. Addition of a mixture of2-chloroethylformal (4044.04 g, 23.38 moles) and 1,2,3-trichloropropane(70.40 g, 0.48 mole) was started at a rate of ˜23.00 g/min. After about14 minutes, addition of aqueous sodium hydroxide (1553.20 g,concentration: 50%; 19.42 moles) was started at a rate of ˜8.63 g/min.Addition of the chlorides lasted for 3 hr while the addition period forthe solution of sodium hydroxide was 3 hr. Reaction temperature wasraised to 212° F. and heating was continued for 4 hr. Reaction mixturewas cooled to ambient temperature. Aqueous layer was removed and thepolymeric layer was washed with five 3000 ml portions of water. The lastwashing was almost free of sodium hydrosulfide as indicated by leadacetate paper test. Polymeric layer was then washed with acidified water(3000 ml water containing 44 ml of glacial acetic acid) followed by fouradditional 3000 ml portions of water. Polymer layer was separated anddried at 190-210° F./2-5 mm for 3 hr; Yield: 2829 g; color: light grey;mercaptan equivalent weight: 1520 (iodine titration method); viscosity:94 Poise (spindle no. 6 @100 RPM, 25° C. Brookfield Cap 2000Viscometer).

Example 6 Synthesis of TDI-Capped Polymer

A 1-liter 4-neck flask was charged with 565.4 g (0.37 equivalent) ofpolymer of Example 5 (equivalent weight: 1520) and the reaction flaskwas evacuated at 170-180° F./1-5 mmHg for 1.5 hr. Vacuum was releasedunder nitrogen and the polymer was cooled to 84° F. Toluenediisocyanate, (TDI; 81.22 g, 0.93 equivalent) was added and mixed for 30minutes. The % isocyanate value of the reaction mixture was 5.835.Polycat 8 (0.02 g, 0.00016 equivalent, N,N-dimethylcyclohexylamine, aproduct of Air Products) was added as a base catalyst at 89° F. Anexotherm developed and raised the reaction temperature to 127° F. in 6minutes. Stirring was continued for 22 minutes. Mercaptan equivalentweight of the reaction mixture was 204,115 at this stage and reactionwas considered to be complete. Benzoyl chloride (0.065 g, 0.0005equivalent), a stabilizer, was added and stirred for 25 minutes. Productwas a viscous liquid; isocyanate equivalent weight: 1203; viscosity: 613Poise (spindle no. 6 @50 RPM, 25° C.; Brookfield Cap 2000 Viscometer).

Example 7 Synthesis of IPDI-Capped Polymer

A 1-liter 3-neck flask was charged with 706.50 g (0.46 equivalent) ofpolymer of Example 5 (equivalent weight: 1520) and the reaction flaskwas evacuated at 170-180° F./1-5 mmHg for 2.5 hr. Vacuum was releasedunder nitrogen and the polymer was cooled to 90° F. Isophoronediisocyanate, (IPDI; 129.55 g, 1.17 equivalent) was added under a flowof nitrogen and mixed for 30 minutes. The % isocyanate value of thereaction mixture was 5.60. Polycat 8 (0.03 g, 0.00024 equivalent,N,N-dimethylcyclohexylamine, a product of Air Products) was added as abase catalyst at 86° F. An exotherm developed and raised the reactiontemperature to 126° F. in 10 minutes. Stirring was continued for 22minutes. Mercaptan equivalent weight of the reaction mixture was 204,115at this stage and reaction was considered to be complete. Benzoylchloride (0.084 g, 0.0006 equivalent), a stabilizer, was added andstirred for 25 minutes. Product was a viscous liquid; isocyanateequivalent weight: 1292; viscosity: 811 Poise (spindle no. 6 @50 RPM,25° C.; Brookfield Cap 2000 Viscometer).

Example 8 Synthesis of Amine-Capped Polymer

A 500-ml 3-necked flask was charged with 316.68 g (0.27 equivalents) ofthe polymer of Example 4 and 53.34 g (0.42 equivalents) of ETHACURE®300, a diamine from Albemarle Corporation. Contents were mixed undervacuum (10 mmHg) for 2.0 hr and vacuum was released under nitrogen.Polycat 8 (0.07 g, 0.0006 equivalents) was added and the mixture washeated at 148-150° C. for 17.5 hr. Product was light brown in color;viscosity: 32 poise (spindle no. 6 @500 RPM, 25° C.; Brookfield Cap 2000Viscometer).

Example 9 Synthesis of Silane-Terminated Polymer

Polymer (317.00 g, 0.16 equivalent), as prepared according to Example 3,was charged into a three-neck 500 mL flask equipped with thermometer,stirrer, condenser and nitrogen inlet/outlet. Silquest® A-171 (24.00 g,0.16 equivalent) was added into the reactor under nitrogen. The contentswere mixed for 10 minutes. The clear reaction mixture was heated up andmaintained at 170° F. Radical initiator Vazo®67 was added into thereactor at an interval of two hours. An excess of Silquest® A-171 (40.00g) was added into the reactor, Mat 8 g per portion, over a period of 72hours. The equivalent ratio of Silquest® A-171 to polymer was 2.7 to 1.Addition of Vazo® 67 was continued until mercaptan equivalent of thereaction mixture was greater than 100,000. The unreacted Silquest® A-171was removed at 170° F. under vacuum. The final product (315 g) was aviscous liquid. Viscosity was 241.5 Poise (Spindle #6@100 rpm, 25° C.;Brookfield Cap 2000 Viscometer).

Example 10 Sealant Formulation

Part A of the sealant formulation was prepared by mixing 0.4 parts byweight of the polymer prepared according to Example 8 and 0.6 parts byweight of the ETHACURE® 300 amine, which is available from AlbermarleCorp. Part B of the sealant formulation was prepared by mixing 7.75parts by weight of the polymer prepared according to Example 6 and 2parts by weight of the Elftex 8 carbon black, which was pre-dried at300° F. for 72 hours. Elftex 8 carbon black is available from CabotCorp. Parts A & B were mixed in a Hauschild mixer at 2500 rpm for 25seconds. A tensile & elongation sample was then made according tomethods in SAE AS5127/1 and was allowed to cure for two days at roomtemperature followed by 24 hours at 140° F. The sealant prepared fromthe above composition exhibited the properties set forth in Table 2.

TABLE 2* Result Property Application Time 3.2 Grams per minute at 10minutes Tack Free Time 30 Minutes 24 Hour Hardness 80 Shore A 14 DaysHardness 72 Shore A Volume Swell - JRF Type I 6.46% (7 days @ 140° F.)Weight Loss- JRF Type I 0.67% (7 days @ 140° F.) Tensile & ElongationStandard Cure 7 Days 1050psi/396% 7 Days at 140° F. in JRF 1001psi/305%Type 1 8 Hours @ 360° F.  971psi/128% Adhesion Tested on Mil C-27725panel Standard Cure 7 days 100% Cohesive Failure** 7 Days at 140° F. inJRF 89 pli, 100% cohesive failure Type I *Tested according to methods inSAE AS5127/1 **Delaminated from aluminum strip

Example 11 Sealant Formulation

Part A of the sealant formulation was prepared by mixing 0.4 parts byweight of the polymer prepared according to Example 8 and 0.6 parts byweight of the ETHACURE® 300 Amine. Part B of the sealant formulation wasprepared by mixing 8.53 parts by weight of the polymer preparedaccording to Example 7 and 2 parts by weight of the Elftex 8 carbonblack, which was pre-dried at 300° F. for 72 hours. Parts A & B weremixed in a Hauschild mixer at 2500 rpm for 25 seconds. A tensile &elongation sample was then made according to methods in SAE AS5127/1 andwas allowed to cure for two days at room temperature followed by 24hours at 140° F. The sealant prepared from the above compositionexhibited the properties set forth in Table 3.

TABLE 3** Result Property Application Time 36 Grams per minute at 1 hourTack Free Time 6 Hours 24 Hour Hardness 69 Shore A 14 Days Hardness 64Shore A Volume Swell - JRF Type I 13.55% (7 days @ 140° F.) Weight Loss-JRF Type I 0.18% (7 days @ 140° F.) Tensile & Elongation Standard Cure 7Days 786psi/499% 7 Days at 140° F. in JRF 821psi/412% Type I 8 Hours @360° F. 444psi/108% Adhesion Tested on Mil C-27725 panel Standard Cure 7days 67 pli, 90% Cohesive Failure 7 days at 140° F. in JRF 107 pli, 100%Cohesive Failure Type I **Tested according to methods in SAE AS5127/1

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentinvention may be made without departing from the invention as defined inthe appended claims.

1. A thioether comprising a structure having the formula:

in which: (a) each R, which may be the same or different, denotes aC₂₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; a C₆₋₈cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀ alkylarylenegroup; (b) each R₁, which may be the same or different, denotes ahydrogen, a C₁₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; aC₆₋₈ cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀alkylarylene group; (c) each X, which may be the same or different,denotes O or S; (d) p has a value of 1 to 5; (e) q has a value of 1 to5; and (f) n has a value of at least 1
 2. The thioether of claim 1,wherein: (a) each R denotes a C₂₋₁₀ n-alkylene group; (b) each R₁denotes a hydrogen; and (c) each X denotes O.
 3. The thioether of claim1, wherein n has a value of at least
 2. 4. The thioether of claim 3,wherein n has a value of no more than
 60. 5. The thioether of claim 4,wherein n has a value of 25 to
 35. 6. The compound of claim 1, wherein:(a) each R denotes a C₂ n-alkylene group; (b) each R₁ denotes ahydrogen; and (d) X denotes O.
 7. The thioether of claim 1, wherein thethioether has the structure:A-(—R³)₂ wherein: (a) A comprises the structure of claim 1; and (b) eachR³, which may be the same or different, comprises a terminal groupselected from —OH, —SH, alkyl, alkylene, —NCO,

amine and silane.
 8. The thioether of claim 1, wherein the thioether hasthe structure:B-(A-R₃)_(z) wherein: (a) B denotes a z-valent residue of apolyfunctionalizing agent; (b) A comprises the structure of claim 1; (c)each R₃, which may be the same or different, comprises a terminal groupselected —SH, —H, —OH, alkyl, alkylene, —NCO,

amine, and silane; and (d) z is an integer from 3 to
 6. 9. A compositioncomprising the thioether of claim
 1. 10. The composition of claim 9,further comprising an additional sulfur-containing polymer.
 11. Thecomposition of claim 10, wherein the additional sulfur-containingpolymer includes a structure having the formula:—R¹—[—S—(CH₂)₂—O—[—R²—O—]_(m)—(CH₂)₂—S—R¹]_(n) wherein: (1) R¹ denotes aC₂₋₆ n-alkylene, C₃₋₆ branched alkylene, C₆₋₈ cycloalkylene or C₆₋₁₀alkylcycloalkylene group, —[(—CH₂—)_(p)—X—]_(q)—(—CH₂—)_(r)—, or—[—(CH₂—)_(p)—X—]_(q)—(—CH₂—)_(r)— in which at least one —CH₂— unit issubstituted with a methyl group; (2) R² denotes a C₂₋₆ n-alkylene, C₂₋₆branched alkylene, C₆₋₈ cycloalkylene or C₆₋₁₀ alkylcycloalkylene group,or —[(—CH₂—)_(p)—X—]_(q)—(—CH₂—)_(r)—, X denotes one selected from thegroup consisting of O, S and —NR⁶—, R⁶ denotes H or methyl; (3) m is arational number from 0 to 10; (4) n is an integer from 1 to 60; (5) p isan integer from 2 to 6; (6) q is an integer from 1 to 5, and (7) r is aninteger from 2 to
 10. 12. A composition comprising two or moresulfur-containing polymers, at least one of the sulfur-containingpolymers comprising a thioether comprising a structure having theformula:

in which: (a) each R, which may be the same or different, denotes aC₂₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; a C₆₋₈cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀ alkylarylenegroup; (b) each R₁, which may be the same or different, denotes ahydrogen, a C₁₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; aC₆₋₈ cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀alkylarylene group; (c) each X, which may be the same or different,denotes O or S; (d) p has a value of 1 to 5; (e) q has a value of 1 to5; and (f) n has a value of at least 1, wherein the thioethers havecoreactive functional groups.
 13. The composition of claim 12, whereinthioether comprises an —NCO capped thioether.
 14. The composition ofclaim 13, wherein the —NCO groups are derived from a polyisocyanatecomprising isocyanate groups having differing reactivity.
 15. Thecomposition of claim 13, wherein the —NCO groups are derived from thereaction product of an aromatic diisocyanate and a sulfur diol.
 16. Thecomposition of claim 13, wherein at least one of the sulfur-containingpolymers comprises an amine/hydroxyl functional thioether.
 17. Acomposition comprising an amine/hydroxy functional thioether comprisinga structure having the formula:

in which: (a) each R, which may be the same or different, denotes aC₂₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; a C₆₋₈cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀ alkylarylenegroup; (b) each R₁, which may be the same or different, denotes ahydrogen, a C₁₋₁₀ n-alkylene group; a C₂₋₁₀ branched alkylene group; aC₆₋₈ cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀alkylarylene group; (c) each X, which may be the same or different,denotes O or S; (d) p has a value of 1 to 5; (e) q has a value of 1 to5; and (f) n has a value of at least
 1. 18. The composition of claim 17,wherein the amine groups are derived from an aromatic amine.
 19. Thecomposition of claim 17, further comprising an additionalsulfur-containing polymer comprising functional groups reactive withamine and hydroxy groups.